There are two basic stages in the performance of root canal therapy on a tooth. In the first stage the root canal is prepared by conically shaping the walls of the canal using graduated root canal files or reamers. The finished wall has a fairly uniform taper from a largest dimension at the coronal portion of the canal to a narrowest dimension at the apical end thereof. The second stage involves the obliteration of the canal by filling it with cones or plugs formed of a deformable or heat moldable material, most typically gutta percha or some similar thermoplastic material. In one method employed, plugs or cones of gutta percha are placed in the canal and heated to plasticize the gutta percha or heated plugs or cones of gutta percha are placed in the canal. In either case the plasticized gutta percha cones in the canal are condensed with an endodontic plugger to compress and compact the material within the canal to seal the apical end and to fill the void of the root canal. In the well known vertical condensation method a small dimensioned plug or cone is first placed in the canal, plasticized by heat and plunged to the apical end of the canal and compressed with pluggers to fill the apical end. A slightly larger diameter plug or cone is next inserted into the canal above the compressed first cone, plasticized and compressed with the pluggers, and this procedure is continued with progressively larger diameter cones until the canal is filled from the apical end to the desired depth.
Root canal therapy with currently available filling cones and endodontic equipment for plasticizing and compressing the cones involves separate emplacing, heating and condensing steps utilizing multiple endodontic instruments. In particular, the step of and equipment for plasticing the cones is cumbersome and difficult, whether the cones are first heated and then inserted into the canal in their softened condition or first inserted in the canal and then heated by contact with a heated instrument.
It is therefore the purpose of the present invention to overcome these currently encountered practical difficulties and to provide a simple and easy to use instrument for emplacing, heating and condensing heat deformable and moldable plugs or cones in a root canal.